1. Field of the Invention
The present invention relates to a current switching device, comprising in a box, at least one polar current path, established between two connecting terminals, with, in series, a break pole formed by at least one stationary contact and at least one mobile contact, a protective thermal tripping device consisting of a bimetal strip surrounded by a heater element and a protective magnetic tripping device consisting of a coil wound around a coil form in which a mobile core slides, the wire of the coil being connected by an intermediate conductor to the end of the heater element.
2. Discussion of the Related Art
In certain protective devices such as cut-out switches or relay switches there is a protective thermal and magnetic module providing a protection against overloads. This thermal-magnetic module comprises a bimetal strip thermal tripping device able to control the opening of the contacts via a tripping mechanism, in response to an overload current.
The thermal-magnetic module also comprises an electromagnetic tripping device provided with a mobile core sliding in a coil form through whose coil the polar current passes. The displacement of the core, in response to an overload or an overcurrent, actuates the opening of the contacts.
The two tripping devices (magnetic and thermal) are housed on the same side of the contact bridge as for example in patent EP-0 237 607. However, this arrangement lengthens the conductive connections between the stationary contact and the bimetal strip and between the magnetic tripping device and the connecting terminal.